Twelve months ago I got an iPhone 8, sans headphone jack. I hadn't been using heaphones much when commuting. I decided it was time to try bluetooth. I toyed with the idea of a BT received for my H6 but ended up deciding to try the BWP7 wireless. They were disappointingly much more V-shaped than the wired version I'd demo's previously. Then the PX came out and so I sold the P7W and tried them. They were a very odd beast. On some recordings they sound lovely, on others they have this strange boxy sound. I gave up at that point and lived with the PX.
Then recently I saw the headfi TV episode that introduced the FiiO BTR3 and...
I'm very happy with this rig for commuting. The BTR3 stays in place really well, it's basically like a wireless H6. The red cable is gone and replaced with the short cable Bluewave sell with their headphone mount kit, it's a bit shorter and doesn't need to wrap around. It's also all black for a stealthier look. I got myself a cheap Sony android phone that's LDAC capable. I've always loved the H6, it's the best of many many closed back portables I've tried over the years. It's one weakness is it is occasionally a little hot in the treble.
I'm on holidays now and have been playing with some simple mods to try to tame the treble. I've discovered the pads come off super-easy, so I first tried small discs cut from non-slip draw liner under the pads. Not much better. So I tried asking some questions on another board I follow that is more heavily into modding. I asked some general questions about how different mods and materials work. Based on the info I got there I tried some cotton make-up removal pads my partner had, they were the perfect size. I think they're somewhere between a cotton felt and cotton wool. Those have definitely reduced the treble more. I need to test them for longer to see whether it's too much. If they do I'll try some thin open-cell foam.